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• Legal issues regarding proprietary_codecs in Electron framework (libffmpeg)

  18 juin 2021, par Manmohan Singh

  We're in the process of building and deploying a desktop based app on electron v 12.0.7. It'll be a (free) commercial software deployed to 2-3M users worldwide.
Recently our legal team enquired about the proprietary codecs bundled with chromium and I thought the best way to confirm this would be to reach out here.

  


  So, here're specific things that I need help with :

  


  


  1. Are we shipping chromium with proprietary codecs ? If yes, what are potentially contentious codecs that come by default in chromium bundled with electron v 12.0.7 ?

     


  


  2. Is there any documentation around how the electron team builds chromium (with what flags) ?

     


  


  3. Is the default libffmpeg.dylib/dll bundled with electron building ffmpeg with support for things like H.264 and MP3 codecs ?

     


  


  4. I noticed there are libffmpeg binaries available with each electron build, e.g. https://github.com/electron/electron/releases/download/v12.0.7/ffmpeg-v12.0.7-darwin-arm64.zip . What's the purpose of this binary ?

     


  


  


  Any help would be appreciated.

  


• Legal issues regarding proprietary_codecs in chromium (bundled with electron)

  4 juin 2021, par Manmohan Singh

  We're in the process of building and deploying a desktop based app on electron v 12.0.7. It'll be a (free) commercial software deployed to 2-3M users worldwide.
Recently our legal team enquired about the proprietary codecs bundled with chromium and I thought the best way to confirm this would be to reach out here.

  


  So, here're specific things that I need help with :

  


  


  1. Are we shipping chromium with proprietary codecs ? If yes, what are potentially contentious codecs that come by default in chromium bundled with electron v 12.0.7 ?

     


  


  2. Is there any documentation around how the electron team builds chromium (with what flags) ?

     


  


  3. Is the default libffmpeg.dylib/dll bundled with electron building ffmpeg with support for things like H.264 and MP3 codecs ?

     


  


  4. I noticed there are libffmpeg binaries available with each electron build, e.g. https://github.com/electron/electron/releases/download/v12.0.7/ffmpeg-v12.0.7-darwin-arm64.zip . What's the purpose of this binary ?

     


  


  


  Any help would be appreciated.

  


• Issues when decoding video via ffmpeg with dxva2

  5 janvier 2016, par CD83

  I have successfully implemented a video player using ffmpeg. I am now trying to use hardware decoding but I’m facing a couple issues.
  I found a post that I followed as a starting point here : http://comments.gmane.org/gmane.comp.video.ffmpeg.libav.user/13523

  I have updated the code that setup the necessary stuff for the decoder. The updated code is available here : https://drive.google.com/file/d/0B5ufHdoDzA4ieVk5UVpxcDNzRHc/view?usp=sharing

  And this is how I’m using it to initialize the decoder :

  // Prepare the decoding context
  
  AVCodec *codec = nullptr;
  
  _codecContext = _avFormatContext->streams[_streamIndex]->codec;
  
  if ((codec = avcodec_find_decoder(_codecContext->codec_id)) == 0)
  
  {
  
      std::cout << "Unsupported video codec!" << std::endl;
  
      return false;
  
  }
  
  
  
  _codecContext->thread_count = 1;  // Multithreading is apparently not compatible with hardware decoding
  
  InputStream *ist = new InputStream();
  
  ist->hwaccel_id = HWACCEL_AUTO;
  
  ist->hwaccel_device = "dxva2";
  
  ist->dec = codec;
  
  ist->dec_ctx = _codecContext;
  
  _codecContext->coded_width = _width;
  
  _codecContext->coded_height = _height;
  
  
  
  _codecContext->opaque = ist;
  
  dxva2_init(_codecContext);
  
  
  
  _codecContext->get_buffer2 = ist->hwaccel_get_buffer;
  
  _codecContext->get_format = GetHwFormat;
  
  _codecContext->thread_safe_callbacks = 1;
  
  
  
  if (avcodec_open2(_codecContext, codec, nullptr) < 0)
  
  {
  
      std::cout << "Video codec open error" << std::endl;
  
      return false;
  
  }

  And here is the definition of GetHwFormat referenced above :

  AVPixelFormat GetHwFormat(AVCodecContext *s, const AVPixelFormat *pix_fmts)
  
  {
  
      InputStream* ist = (InputStream*)s->opaque;
  
      ist->active_hwaccel_id = HWACCEL_DXVA2;
  
      ist->hwaccel_pix_fmt = AV_PIX_FMT_DXVA2_VLD;
  
      return ist->hwaccel_pix_fmt;
  
  }

  When I open an mp4 (encoded in h264) video that is HD resolution or less, everything seems to be working fine. However, as soon as I try higher resolution videos like 3840x2160, I get the following errors repeatedly :

  Failed to execute: 0x80070057
  
  Hardware accelerator failed to decode picture

  I also start getting the following errors after a few seconds :

  co located POCs unavailable

  And the video is not displayed properly : I get a lot of artifacts all over the video and it is lagging. I checked the first error in the ffmpeg source code. It seems that IDirectXVideoDecoder_Execute fails because of an invalid parameter. Since this is happening withing ffmpeg, there must be something that I’m missing but I can’t figure out what. The only relevant post that I found with this error was because of multithreading but I set the thread_count to 1 before opening the codec.

  This issue is happening on my main computer which has the following specs :

  • i7-4790 CPU @ 3.6GHz
  • RAM 16 GB
  • Intel HD Graphics 4600
  • Windows 8.1

  The same issue is not happening on my second computer which has the following specs :

  • i7 4510U @ 2GHz
  • RAM 8 GB
  • NVIDIA GeForce GTX 750Ti
  • Windows 10

  If I use DXVAChecker on my main computer, it says that my graphics card supports DXVA2 for H264_VLD_*, and I can see that the calls to the Microsoft API are being made (DXVA2_DecodeDeviceCreated, DXVA2_DecodeDeviceBeginFrame, DXVA2_DecodeDeviceGetBuffer, DXVA2_DecodeDeviceExecute, DXVA2_DecodeDeviceEndFrame) while my video is playing.

  I also don’t see any increase of GPU usage (on either computer) between the version with hardware decoding and the version without ; however, I do see a decrease in CPU usage (not as much as I was expecting though). This is also very strange.

  Note that I tried both the Windows release available on the FFmpeg website, and a version that I compiled with —enable-dxva2. I have searched a lot already but I was unable to find what I’m doing wrong.

  Hopefully, someone can help me, or maybe point me to a better example ?